A conventional angular velocity sensor is described below.
The conventional angular velocity sensor calculates an angular velocity, for example, by causing an oscillator having one of various shapes including the shape of a tuning fork, an H shape and a T shape to oscillate and electrically detect a distortion of the oscillator resulting from the production of a Coriolis force. Such an angular velocity sensor is used in navigation apparatuses and vehicle control apparatuses installed in vehicles.
For example, in an angular velocity sensor for a navigation apparatus, if a vehicle is placed on a XY plane defined by X-axis and Y-axis with X-, Y-, and Z-axes being orthogonal to each other, an angular velocity about Z-axis (yaw-axis) of the vehicle needs to be calculated.
The oscillator used in this angular velocity sensor is normally so disposed as to stand upward in the vehicle, i.e. along Z-axis. Upon an angular velocity about the Z-axis, a distortion resulting from a Coriolis force is produced in a direction orthogonal to oscillating directions of the oscillator on the XY plane. This distortion is detected to calculate an angular velocity.
For example, Japanese Unexamined Patent Publication No. 2003-227844 is known as a prior art document relating to the present invention.
The oscillator having the above construction basically needs to be used while standing on the plane orthogonal to an axis of rotation of the angular velocity to be calculated. Thus, there has been a problem of being unable to reduce the height of the angular velocity sensor along a direction of the axis of rotation due to the height of the oscillator.